The invention relates to the housing of an open-end spinning machine and more particularly to the sealing of the shaft of the spinning rotor thereof. In order to prevent penetration of air into a rotor housing, which is under reduced pressure during spinning, it has already been proposed to provide air damming spaces between a bore located in a rear wall of the rotor housing for passage of the rotor shaft and an annular collar of the shaft, and additionally to fasten a sealing washer to these means within the rotor housing. The washer has an opening through which the rotor extends which is smaller in diameter than the diameter of the bore. The section of the rotor shaft upon which the washer is carried is smaller than the annular collar (DE OS No. 2,424,919).
Disadvantages of this solution are firstly that the sealing washer only effects a seal in combination with special rotor shafts with annular collars, and its application is thereby restricted, quite apart from the associated cost. The use of annular collars necessitates, apart from this, an increase in the distance between the rotor and the mounting for the rotor shaft (not shown). Any unbalance can hence be amplified and act on the mounting, stressing it unduly. The combination of a rotor shaft with an annular collar and a sealing washer, necessary for sealing, furthermore leads to an increased cost when the spinning rotor is changed, since either the sealing washer is withdrawn with the rotor shaft from the rotor housing and then either has to be separated from the rotor shaft and inserted into the housing, or special means have to be provided for enlarging the passage opening in order to be able to draw the annular collar through this opening.